A magnesium doped ferrihydrite-humic acid coprecipitation (Mg-doped Fh-HA) was synthesized by coprecipitation method.The removal of heavy metals such as Pb(Ⅱ) and Cd(Ⅱ) was assessed.The isotherms and kinetic studies indicated that the Mg-doped Fh-HA exhibited a remarkable Pb(Ⅱ) and Cd(Ⅱ) sorption capacity (maximum 120.43 mg/g and 27.7 mg/g,respectively.) in aqueous solution.The sorption of Pb(Ⅱ) and Cd(Ⅱ) onto best fitted pseudo-second-order kinetic equation and Langmuir model.The adsorption mechanism of Mg-doped Fh-HA on Pb(Ⅱ) and Cd(Ⅱ) involves surface adsorption,surface complexation and surface functional groups (such as carboxyl group,hydroxyl group).In addition,ion-exchange and precipitation cannot be ignored.The Mg-doped Fh-HA is a low-cost and high-performance adsorption material and has a wide range of application prospects.